Before
After
FRP vs. Traditional Materials
Traditional building materials have their place. But for harsh, corrosive environments, FRP is a smart
choice. Here’s how FRP compares to several traditional options.
FRP Composites
Pultruded GFRP
Steel
A 709 Grade 50
Aluminum
6061-T651 & 6061-T6
Wood
Douglas Fir
Corrosion,
Rot AND Insect
Resistance
Resists a broad range of
chemicals and is unaffected by
moisture or immersion in water.
Resists insect damage. Painting
is only suggested when exposed to
UV rays/direct sunlight.
Subject to oxidation and
corrosion. Requires painting
or galvanizing for many
applications.
Can cause galvanic
corrosion. (Anodizing and
other coatings increase
corrosion resistance.)
Can warp, rot and decay
when exposed to moisture,
water and chemicals.
Susceptible to attack by
insects such as termites and
marine borers.
Strength
Has greater flexural strength
than timber and pound-for-pound
is often stronger than steel
and aluminum in the lengthwise
direction.
Ultimate flexural strength (Fu):
LW = 30,000 psi (30 ksi)
CW = 10,000 psi (10 ksi)
Compression strength:
LW = 30,000 psi (30 ksi)
CW = 15,000 psi (10 ksi)
Homogeneous material.
Yield strength (Fy)
= 36 ksi
Homogeneous material.
Flexural strength (Fu)
= 35 ksi
Modulus of rupture
is 12,000 psi
Lightweight — about a third
of the weight of copper or
steel.
Specific gravity
0.48
Conducts electricity.
Grounding potential.
Conducts electricity.
Grounding potential.
Can be conductive
when wet.
Conducts heat.
Thermal conductivity
= 260-460 (BTU/sf/
hr/°F/in.)
Thermal coefficient of
expansion.
= 6 - 8 (in./in./°F) 10-6
Conducts heat.
Thermal conductivity
= 150 (BTU/sf/hr/°F/in.)
Thermal coefficient of
expansion.
= 13 (in./in./°F) 10-6
Low thermal conductivity.
Thermal conductivity
= .8 (BTU/sf/hr/°F/in.)
Thermal coefficient of
expansion.
= 1.7 - 2.5 (in./in./°F) 10-6
Weight
Weighs 75% less than steel
and 30% less than aluminum.
Electrical
Conductivity
Nonconductive. High dielectric
capability.
Thermal
Properties
Good insulator with low thermal
conductivity.
Thermal conductivity
= 4 (BTU in. /(hr ft2 °F)
Low thermal coefficient of
expansion.
= 7 - 8 (in./in./°F) 10-6
Could require lifting
equipment
to move and place.
1/2-in. thick plate
= 20.4 lbs/sq ft
FRP Composites
Pultruded GFRP
Stiffness
Up to 3.3 times as rigid as
timber. Will not permanently
deform under working load.
Modulus of elasticity:
2.8 x 106 psi
Impact
Resistance
Will not permanently deform
under impact. Glass mat in
pultruded parts distributes impact
load to prevent surface damage,
even in subzero temperatures.
Steel
A 709 Grade 50
Aluminum
6061-T651 & 6061-T6
Wood
Douglas Fir
Modulus of elasticity:
29 x 106 psi
Modulus of elasticity:
10 x 106 psi
Modulus of elasticity:
up to 1.6-1.8 x 106 psi*
Can permanently deform
under impact.
Easily deforms under
impact.
Can permanently deform
or break under impact.
Not hazardous.
Not hazardous.
May be treated with
hazardous preservatives
or coatings to increase
corrosion/rot/insect
resistance. Contributes to
depletion of forest systems.
Must be painted for color,
and may require repainting
over time.
Colors require prefinishes,
anodic coatings and paints.
Mechanical, chemical and
electroplated finishes can
be applied.
Must be primed and painted
for color, and may require
repainting over time.
Has a lower initial cost,
but usually requires
more maintenance and
replacement.
Environmental
Impact
Not hazardous to the
environment.
Color
Color is molded through; no
painting required.
Variety of colors available.
Cost
Lower installation costs, less
maintenance and longer product
life allow for a lower lifecycle
cost.
Lower initial material cost.
Part price comparable
to FRP.
EMI/RFI
Transparency
Transparent to radio waves and
EMI/RFI transmissions. Used for
radar and antennae enclosures
and supports.
Can interfere with EMI/RFI
transmissions.
Highly reflective to
EMI/RFI transmissions.
Transparent.
Fabrication
Can be field-fabricated using
simple carpenter’s tools with
carbon or diamond tip blades —
no torches or welding required.
Light weight allows easier
transport and installation.
Often requires welding and
cutting torches. Heavier
material requires special
equipment to erect and
install.
Good machinability
(welding, brazing, soldering
or mechanical joining).
Can be field-fabricated
using simple
carpenter’s tools.
12% moisture content
*
Compare the Numbers ...
Property
Density (lb/ft 3)
Tensile Strength (psi)
Tensile Modulus (x 106 psi)
Flexural Strength (psi)
Flexural Modulus (x 10 psi)
6
FRP Composites
Pultruded GFRP
Steel
A 709 Grade 50
Aluminum
6061-T651 & 6061-T6
Wood
Douglas Fir
107-120
490
169
30
30,000 (LW)
7,000 (CW)
65,000
45,000
—
2.8 (LW)
1 (CW)
30
10
—
30,000 (LW)
10,000 (CW)
65,000
45,000
12,000
1.8 (LW)
Thermal Conductivity (BTU in. /(hr ft 2 °F))
Thermal Expansion (x 10 in./in./°F)
-6
LW = Lengthwise / CW = Crosswise
References:
1. Datasheets from www.matweb.com
2. Wood Handbook: Wood as an Engineering Material
30
10
1.6 - 1.8
4
0.8 (CW)
323
1,160
0.8
7 to 8
6 to 8
13
1.7 to 2.5